The invention relates to a labeling machine for labeling objects such as bottles, consisting of a labeling station and a transport means for the objects, especially a turntable which moves the objects on controlled revolving platforms past a labeling station and has elements for applying the labels to the objects, the labeling station having at least one label pickup element provided with a convexly curved pickup surface and mounted and driven on a revolving carrier in a rotating or rocking movement by means of a shaft disposed at a fixed distance from the carrier axis, especially between the pickup surface and the center of its curvature, such that, in moving past a plurality of successive stations, such as a gluing device a label supply station, a label transfer station and an inking station, upon each rotation of the carrier the pickup element rolls its pickup surface against the uppermost, especially planar label of the label supply station and against the other stations, and consisting of a label marking station having at least one marking type disposed in an especially convexly curved field, which can be inked at an inking surface in an inking station, and on which the label-bearing pickup surface of each pickup element can be rolled upon rotation of the carrier.
In a known labeling station of this kind (U.S. Pat. No. 4,162,181), the practical construction of the required linkage and geometry between the marking element and the pickup element offers no problems, so that an optimum rolling of the marking type field against the pickup element in the area of the label that is to be imprinted is assured. In high-production labeling machines, however, difficulty is still involved in the practical achievement of the inking of the types by the inking ribbon or roller; the longer the marking type field is in the direction of rotation, the more problematical is the inking.
Whether the inking is performed by means of a ribbon running in synchronism with the type field or by means of a synchronized inking roller, the mechanical design is complex. In the case of a ribbon, the ribbon must be compliant in the radial direction of the carrier so as to be able to compensate for the different radial distance of the marking type field during rotation. For this purpose, an ink applicator roll runs under spring bias on the free length of the ink ribbon. If the inking of the marking type is performed by an inking roller and the marking type field exceeds a certain length, two or even three inking rollers must be disposed in tandem in the direction of rotation of the marking element so as to ink the marking type field in sections. A plurality of inking rollers requires an ink feeder roller for each. In such inking rollers the different radial controlling of the marking type field is compensated by yielding quality of the resilient periphery of the inking roller. In neither of the two cases can a uniform inking be achieved over the entire type field, in spite of the complexity of the design.
In another, older patent application, (German Pat. No. 3,118,775.5) not previously published, these disadvantages are avoided by the fact that the running direction of the inking roller or of the inking ribbon is across the running direction of the marking element, and that the inking roller or inking ribbon is given a concave profile on its outer periphery such that the type field rolls against the outer periphery when it rocks or turns.
While in the state of the art the effort was made to achieve the inking by synchronism between the marking type field and the inking roller or inking ribbon, the rolling is achieved in accordance with the invention exclusively by means of the geometry of the inking roller or inking ribbon, which is stationary while the marking element rotates or rocks. This kind of inking can be achieved constructionally in a comparatively simple manner.
In both of these labeling machines it is disadvantageous that the drying of the ink transferred to the label takes a certain amount of time. During this time the danger exists that the wipers which are to flatten the label fully against the bottle after it has been transferred thereto by the label transfer station, may smear the printing ink. The drying time, therefore, is a factor that limits the output of the machine.